This invention relates to storage batteries for motor vehicles, and more particularly to an enclosure for protecting such batteries from hot underhood temperatures.
The automotive industry has recognized the need to protect motor vehicle batteries from the hot temperatures present in the vehicle engine compartment during operation of the vehicle. It is well established that subjecting the storage batteries to such heating accelerates corrosion of the battery grids which is a major factor in shortening of the lifetime of the battery. Conventionally, vehicle batteries are protected from underhood heating by placing an insulating shell or shield over the battery. Generally, the shield acts as an insulator, but the shield may be designed to provide an air gap between the sidewalls of the battery and the shield through which cooler outside air is circulated either by fan or as the result of vehicle motion. Typically, the insulating shell is mounted on the battery after the battery has been installed in the vehicle. However, it is generally recognized in the automotive industry that subassembly of the insulating shell with the battery prior to the final assembly line will reduce overall costs.
In U.S. Pat. No. 5,212,025 which was issued to Osamu Shibata et al. on May 18, 1993, there is disclosed a storage battery for automobiles which includes a heat shield that is designed to be a part of the battery assembly, making it easier to mount the battery in an automobile. The heat shield is a box-like structure having a closed bottom and which is open to the top to permit the battery to be positioned within the heat shield. The cover of the battery includes an overhang which extends downwardly from the peripheral edge of the cover, spaced outwardly from the sidewall of the battery container, defining a gap which receives the upper edge of the heat shield. This arrangement defines a space between the battery container and the heat shield that is closed to air outside of the heat shield. The heat shield is designed to be attached securely to the battery container. To this end, the battery container has recesses formed in its sidewalls for receiving projections on the heat shield to detachably secure the heat shield to the battery. Although it appears that this arrangement would provide improved thermal insulation for the battery, the arrangement requires a non-standard cover for the battery to define the air gap and a non-standard container to provide the latching recesses in its for securing the heat shield to the battery. Also, because the heat shield has a closed bottom, the battery must be lifted in order to position it within the heat shield. In addition, this arrangement requires modification of the battery hold down tray and hold down hardware.